Thomas j



(No Model.)

T. J. DONOVAN.

ELECTRIC HEATER.

110,446,831. Patented Feb. 17,1891.

UNITED STATES PATENT OFFICE.

THOMAS J. DONOVAN, OF CHICAGO, ILLNOIS, ASSIGNOR TO VAL'IER G. GOODRICll, OF SAME PLACE.

ELECTRIC HEATER.

SPECIFICATION forming part of Letters Patent No. 446,831, dated February 17', 1891.

Application tiled January 20,1890. Serial No. 337,453. (No model.) i

To all whom it may con/cern.:

Be it known that l, THOMAS J. DONOVAN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Electric lleaters, of which the following is a specification.

My invention relates to the heating of iiuids and generation ot steam by electricity, and will be described,and then more particularly pointed out in the claims.

In the drawings like letters rei'er to the saine parts in the several ligures.

Figure l is a vertical longitudinal section of a boiler with one form of my invention applied thereto. Fig. 2 is a similar section ot a tube containing the wires and one of the heaters in a recumbent position. Fig. S is a seetion of a portion ot' the tube and one of the heaters in its operative position. Fig. fi is a cross-section through the line 0c .frj Fig. 2. Fig. 5 is a similar view on the line 1/ y, Fig. 2; and Fig. (i is a detail showing the rod connected with an arm for turning the heater.

vIn carryin g out my invention I First prod ucc heat electrically by any of the well-known methods, but preferably by rendering incandescent any suitable filament, such as platinum, carbon, tbe., and then inelose the heatemitting 'substance 'in an air-tight envelope from which the atmosphere has been exhausted. This envelope is not of glass, but ot some material-such as metal-which will readily become heated by radiation from the incandescent n'lainent or other heat-emitting substance. The envelope should of course not touch the filament or other heat-emittin g substance, but should be at such a distance as will eiicctively insulate it electrically, and at the same time enable itto absorb the radiated heat,

In Fig. l l have shown a manner of applying one form of my invention to an ordinary boiler ce According to this method of construction l provide the boiler with a stuliingbox upon its exterior and upon its interior with an inward]y-opening flap-valve c, which latter is usually held closed by the pressure of the steam. A tube h is provided on one side with a concave depression extending along its entire length, in which a series of heaters lie horizontally when not. in use. This tube, with the heaters, is passed into the boiler through an aperture therein which the stutting-box surrounds, and in its passage lifts the flap valve c out of the way. Oi course there may be a number of tubes l), and one or all may be withdrawn or replaced at pleasure. The wires from the generator extend along the interior of the tube, and at suitable intervals one ofthe wires is broken and its severed ends passed through a block ot' vulcanite or other insulating material, in which are separately embedded two conductin g-terminals CZ d.

The heater is provided on one side with a conducting-bridge e, which connects the terminals (l (Z when the heater is in a recumbent position. The Filament g ot' the heater is properly insulated where it passes through the met-al parts thereof and connects with two conducting-terminals f j', which in the vertical and operative condition ol the heater abut against the corresponding terminals d d of the tube, and so make a circuit through theheater. Thus when the heater is reeumbent the circuit is made through the bridge, and when the heater is in operative position the circuit is made through the terminals and the filament.

rlhe pivot of the heater is mounted in the tube, and near one end of such pivot, within the tube, is an arm yI. A rod 7;. lies within the tube and extends tothe outer end thereof. This rod is secured to the arms et the several heaters, so that they can be manipulated from the outside.

Surrounding the ilament or other heatemitting substance is an envelope 7L of heatradiating material-sueh as metal-which is air and water tight and has its atmosphere exhausted therefrom. The inner walls of this envelope are at such a dist-ance from the filament as to be insulated electrically, and at the same time to absorb the heat radiating therefrom and communicate the same to the surrounding fluid medium, so as to heat such iiuid and manufacture steam.

I have shown and described one way oi carrying my invention into effect; but I do not mean to limit myself thereto, for it is obvious that instead of a filament. an are light may be TOO used, and the details of the invention may bcmodified in various particulars without dcparting from the spirit thereof.

vVlhat I claim, and desire tosecure by Letters Patent, is-

1. The combination of a boiler or other fluidreservoir, an electrically-heated substance lnclosed in an envelope from which the air has been exhausted, and a removable carrier for such envelope normally insertedin the boiler or reservoir, substantially as shown and described.

2. The combination of a boiler or otherrluid-l reservoir, and one or more detachable carriers for electric heaters,which are designed tofbe placed in such reservoir, substantially as shown and described.

3. The combination of la fluid-reservoir and one ormore-oarriers having depressions or compartments for containing electric heaters,

ulating such pivoted heaters, substantially as l shown and described.

THOMAS J. DONOVAN. Witnesses:

FREDERICK SEARLE, JAMESKEENAN. 

